﻿using System;
using System.Net.Http.Headers;

namespace ConsoleApp4
{
    class Program
    {
        static void easy(string[] args)
        {
            const double pi = 3.1415926;

            const Single pp = 3.14F;

            double r = 12;

            double area = pi * r * r;

            Console.WriteLine(area);
               
        }
    }
    class userrol
    {
        static void Main(String[] args)
        {
            var res = 2 > 1;
            int num = 10;
            //最简单的判断语句
            if (true)
            {
                Console.WriteLine("你是对的");

            }
            //有两个分值的判断语句
            if (res)
            {
                Console.WriteLine("看到这个说明对了！");
            }
            else
            {
                Console.WriteLine("看到这个，说明你错了！");
            }
            //有多个分支的判断语句
            if (num > 5)
            {
                Console.WriteLine("大于5");
            }
            else if(num>4)
            {
                Console.WriteLine("大于4");

            }
            else if (num > 3)
            {
                Console.WriteLine("大于3");

            }
            else
            {
                Console.WriteLine("小于等于3");

            }
            int points = 93;

            switch (points/10)
            {
                case 10:
                    Console.WriteLine("优秀");
                    break;
                case 9:
                    Console.WriteLine("优秀");
                    break;
                case 8:
                    Console.WriteLine("良好");
                    break;
                case 7:
                    Console.WriteLine("及格");
                    break;
                case 6:
                    Console.WriteLine("及格");
                    break;
                default:
                    Console.WriteLine("不及格");
                    break;
            }



        }
        

    }

}
 